General Science MCQ Practice

• Correct option: B — Formic Acid
• Why: Certain ants (formicine ants) release formic acid as a defensive bite/sting to deter predators.
• Key concept: Formic acid (HCOOH) is produced by ants; it causes irritation on skin or mucous membranes.
• Rule/brief formula: HCOOH (simple carboxylic acid) — identification by association with ant secretions.
• Exam tip: If a question mentions ant bite or formic secretion, choose Formic Acid.
• Other options: A, C, D are not typical ant bite secretions.

• Key concept: Xylem conducts water and mineral nutrients from roots to leaves, using transpiration pull and vessel elements.
• Why correct: Xylem vessels are designed for unidirectional flow of water from roots upward; food (sugars) moves in phloem, not xylem.
• Other options:
  • A (food) – transported by phloem as photosynthates.
  • C (nutrient) – minerals travel dissolved in water via xylem, not as a separate transport of "nutrients" alone.
  • D – incorrect since xylem does not transport food.

Exam tip: Remember: Xylem = water + minerals; Phloem = food (sugars).

• Correct answer: A — Environment.
• Explanation: The Kyoto Protocol is an international environmental treaty under the UN Framework Convention on Climate Change to reduce greenhouse gas emissions.
• Key concept: greenhouse gases (CO2, CH4, N2O) and binding emission targets.
• If needed: the idea is measured as emissions in CO2-equivalent (CO2e) to compare different gases.
• Exam tip: Remember treaties like Kyoto relate to global environmental protection, not nuclear power or trade.
• Why others wrong: B and C are unrelated; D is incorrect because Kyoto exists.

• Why correct: Green leafy vegetables are rich in folic acid (vitamin B9), essential for DNA synthesis and cell division.
• Key concept: Folic acid is abundant in leafy greens like spinach and kale; other acids are more common in fruits.
• Formula/numerical logic: Not required here.
• Exam tip: Remember “folic” with leafy greens—B9 key for pregnancy and growth.
• Why others are incorrect: Citric acid (A) and malic acid (B) are mainly in citrus and apples; not characteristic of leafy greens.

• The correct answer is B. oilseeds.
• “Yellow Revolution” refers to rapid increase in production of oilseeds in India, driven by improved varieties, better inputs, and farming practices.
• Key concept: agricultural revolutions map to different crops; Green for cereals, Yellow for oilseeds, White for milk.
• There is no formula needed here; the concept is agricultural production trends.

• Why correct: Iron is essential for heme in hemoglobin; without it, red blood cells cannot carry oxygen well, causing anemia.

• Answer: F. Banting
• Why correct: Frederick Banting, with Charles Best, discovered insulin in 1921, enabling life-saving treatment for diabetes. The key concept is the isolation of insulin from the pancreas to regulate blood glucose.
• Brief note: The discovery showed that pancreatic extracts can lower blood sugar in diabetics.
• Why others are incorrect: Salk developed polio vaccine; Fleming discovered penicillin; Roentgen x-rays—none related to insulin.
• Exam tip: Remember “Banting & Best” as insulin founders; focus on the insulin-pantreatic relation to diabetes treatment.

• Correct option: D — Forests.
• Why correct: Silviculture studies the cultivation and care of forests to improve growth, quality, and composition of trees.
• Key concept: Forest management, wood production, and ecological sustainability; involves practices like planting, thinning, pruning, and protection.
• Formula/numerical logic: Not required here; concept is qualitative.
• Why others are incorrect: Rivers (A), lakes (B), and hills (C) are not forest systems; their management falls under hydrology or land-use planning, not silviculture.
• Exam tip: Remember: silviculture = management of forests to optimize yield and health.

• Reason: SO2 released from pollution converts to sulfurous/sulfuric acids in rain, accelerating the chemical weathering of marble (CaCO3) used in the Taj Mahal.
• Key concept: Acid rain chemistry; acids react with carbonate rocks, speeding dissolution.
• Minimal formula: SO2 + H2O → H2SO3 (and later H2SO4 in the atmosphere).
• Exam tip: Questions on monuments often link pollution-caused acid rain to stone decay.
• Why others are incorrect: CO2 and water vapour do not cause as rapid acid attack; CO is not a major atmospheric oxidant driving marble decay at relevant scales.